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Search Results: 1 - 10 of 720 matches for " Udo Broll "
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Low and Highly Skilled Labor Immigration and Wage Inequality  [PDF]
Beate Wojtyniak, Udo Broll, Sugata Marjit
Technology and Investment (TI) , 2010, DOI: 10.4236/ti.2010.12011
Abstract: Fears of rising income inequalities loom large in recent discussions of how globalization and in particular migration are affecting economies and societies [1]. This paper addresses the question how labor immigration is related to wage inequality by using a specific-factors trade model. We show that the impact of immigration of low or highly skilled labor on wage inequality depends mainly on the capital intensity of the industry in which labor immigrates.
Banking Firm, Risk of Investment and Derivatives  [PDF]
Udo Broll, Wing-Keung Wong, Mojia Wu
Technology and Investment (TI) , 2011, DOI: 10.4236/ti.2011.23023
Abstract: The economic environment for financial institutions has become increasingly risky. Hence these institutions must find ways to manage risk of which one of the most important forms is credit risk. In this paper we use the mean-variance (mean-standard deviation) approach to examine a banking firm investing in risky assets and hedging opportunities. The mean-standard deviation framework can be used because our hedging model satisfies a scale and location condition. The focus of this study is on how credit risk affects optimal bank investment in the loan and deposit market when derivatives are available. Furthermore we explore the relationship among the first- and second-degree stochastic dominance efficient sets and the mean-variance efficient set.
Farmer`s Income from Production and Financial Assets
Udo Broll,2Kit Pong Wong
Pakistan Journal of Social Sciences , 2012,
Abstract: This paper examines the optimal production and hedgeable decisions of a risk- averse farmers facing both hedgeable price risk and non-hedgeable income risk. While the separation property holds in this context, the full-hedging property does not. The correlation between the non-hedgeable income risk and the hedgeable price risk is pivotal JEL: F21
Diversity of soil organisms in alpine and arctic soils in Europe. Review an research needs
Broll, Gabrielle
Pirineos : Revista de Ecología de Monta?a , 1998,
Abstract: The diversity of soil organisms and soil ecological processes in different mountain regions of Europe are reviewed. Detailed taxonomic studies on soil organisms have been made in the Alps and in Northern Europe since the end of the last century, however, there is a paucity of data from Southern Europe. Future studies could include the re-sampling of historic study sites to assess if there has been a change in the soil fauna and microorganisms. The role of key abiotic processes such as cryoturbation should be quantified and further research should focus on identifying indicator organisms, keystone species and functional groups. In addition, studies on soil organic matter and particularly on humus forms, the products of soil ecological processes should be encouraged. Ecotones, where the influence of spatial heterogeneity on soil biodiversity is likely to be particularly pronounced, appear to be the most rewarding for such studies. [fr] La diversité des organismes du sol et les différents processus écologiques ayant lié dans les diverses régions de montagne en Europe sont détaillés. Des études approfondies sur la taxonomie des organismes du sol ont été développées dans les Alpes et en Europe du Nord depuis la fin du siècle dernier, mais par contre il y a peu de données sur l'Europe du Sud. Dans l'avenir on pourrait re-étudier les sites bien connus de fa on à savoir s'il y a eu de changements dans la faune et les microorganismes du sol. Il faudrait quantifier le r le des processus abiotiques comme la cryoturbation, identifier les organismes indicateurs, les espèces-clé et les groupes fonctionnels. Il est aussi indispensable de développer les études sur la matière organique et en particulier les types d'humus, en tant que résultat des processus écologiques du sol. Les ecotones, dans lesquels l'influence de l’heterogeneité spatiale sur la biodiversité du sol est particulièrement prononcée, semblent les plus pertinents pour de telles études. [es] Presentamos una revisión de los organismos del suelo y de los procesos ecológicos edáficos en las diferentes zonas de monta a de Europa. En los Alpes y en Europa septentrional se han llevado a cabo estudios taxonómicos detallados sobre los organismos del suelo, pero tenemos pocos datos de Europa meridional. De cara al futuro se tendrían que volver a muestrear los parajes que dieron lugar a estudios clásicos, de modo que se pudiera comprobar si ha habido cambios en la edafofauna y en los microorganismos. Convendría también cuantificar los procesos abióticos como la crioturbación y atender a la identificación de organis
Subalpine Forest and Treeline Ecotone under the Influence of Disturbances: A Review  [PDF]
Friedrich-Karl Holtmeier, Gabriele Broll
Journal of Environmental Protection (JEP) , 2018, DOI: 10.4236/jep.2018.97051
Abstract: This article considers disturbances caused by abiotic and biotic factors and human impact in the ecological region extending from subalpine forest to the upper tree limit. Both abiotic and biotic factors may cause reversible or irreversible disturbances. Disturbances by mass movement and avalanches give the subalpine forest and the treeline ecotone a distinct spatial pattern characterized by forest on safe topography and sites that preclude forest. Removal of the upper subalpine forests by humans has enlarged the snow-catchment area of avalanches and elongated the avalanche pathways. Consequently, avalanche destructive potential has increased. Hazards will probably increase due to climate change. External factors, like cyclonic storms, may cause fundamental disturbances. Fires have played a major role in the removal of high-elevation forests. Forest destruction by fire is often followed by soil erosion. Wild fires are likely to increase as a result of warming climate and would possibly prevent climatically-driven treeline advance. Cyclic or episodic mass outbreaks of defoliating insects and bark beetles, and pathogens also cause severe disturbances. Oversized populations of wild ungulates impede tree regeneration and can cause local soil erosion. Inadequate game management is the primary cause of intolerable ungulate numbers. Due to man-caused habitat fragmentation, the animals’ impact on the remained habitats has increased. Subalpine forest may recover from disturbance or become replaced by a substitute formation (e.g. krummholz). A subsequent absence of natural disturbances may also be considered a disturbance initiating a new development. Both natural and anthropogenic disturbances may counteract positive influences of climatic warming on subalpine forests and treeline. Effective measures to reduce or prevent abiotic and biotic disturbances of high-elevation forest may contribute to greater safety for people living in the endangered areas of the mountain valleys and also improve other ecosystem services of the subalpine forest.
Error Corrected Sub-Monolayer Ellipsometry for Measurement of Biomolecular Interactions  [PDF]
Udo Riss
Open Journal of Biophysics (OJBIPHY) , 2013, DOI: 10.4236/ojbiphy.2013.31A010
Abstract:

Already in 1946 Alexandre Rothen from the Rockefeller Institute for Medical Research, New York published the use of ellipsometry for the measurement of antigen-antibody interactions. And he found some effects that could not be explained by the assumption that the interaction of the molecules is only of chemical nature. 55 years later we started research on antibody-antigen interaction and found similar results. To make sure that these measurements are not produced by measurement artifacts, each component of our measurement technique is error analyzed and error corrected if necessary. With such type of error corrected instrumentation we found, that there must be an interaction between antigens and antibodies that is based on longitudinal electromagnetic waves, which are able to work through thin 7 nm membranes. A similar interaction is found for the virus-antigen interaction. Our measurement results are in contrast to the assumption that the antigen-antibody and antigen-virus interaction is only of chemical nature.

Theory of affinity maturation of antibodies  [PDF]
Udo Riss
Advances in Bioscience and Biotechnology (ABB) , 2013, DOI: 10.4236/abb.2013.44A010
Abstract:

Based on the theory of long distance interaction between antibodies and antigens we developed a theory of affinity maturation of antibodies that is based on longitudinale electric waves. Early stage antibodies show a wide frequency spectrum for antigens and are polyspecific. After affinity maturation the antibody shows a very narrow band spectrum, the antibodies become monospecific. The feedback between antibody and antibody producing cell is done via messenger molecules that are also communicating with help of longitudinal electric waves. These messenger molecules transfer information from antibody arms and are informing cells whether the epitopes are switched on or off. The folding of antibody is done via eigen frequency resonances.

An Analytical Theory of the Signal-to-Noise Ratio of Hall Plates with Four Contacts and a Single Mirror Symmetry  [PDF]
Udo Ausserlechner
Journal of Applied Mathematics and Physics (JAMP) , 2018, DOI: 10.4236/jamp.2018.610174
Abstract: This work gives an analytical theory of the signal-to-thermal-noise ratio (SNR) of classical Hall plates with four contacts at small magnetic field. In contrast to previous works, the symmetry of the Hall plates is reduced to only a single mirror axis, whereby the average of potentials of the two output contacts off this mirror axis differs from the average of potentials at the two supply contacts on the mirror axis, i.e. the output common mode differs from 50%. Surprisingly, at fixed power dissipated in the Hall plate, the maximum achievable SNR is only 9% smaller for output common modes of 30% and 70% when compared to the overall optimum at output common modes of 50%. The theory is applied to Vertical Hall effect devices with three contacts on the top surface and one contact being the buried layer in a silicon BiCMOS process. Geometries are found with large contacts and only a moderate loss in SNR.
A super-spreading ewe infects hundreds with Q fever at a farmers' market in Germany
Klaudia Porten, Jürgen Rissland, Almira Tigges, Susanne Broll, Wilfried Hopp, Mechthild Lunemann, Ulrich van Treeck, Peter Kimmig, Stefan O Brockmann, Christiane Wagner-Wiening, Wiebke Hellenbrand, Udo Buchholz
BMC Infectious Diseases , 2006, DOI: 10.1186/1471-2334-6-147
Abstract: In exploratory interviews patients mentioned having visited a farmers' market where a sheep had lambed. Serologic testing confirmed the diagnosis of Q fever. We asked local health departments in Germany to identiy notified Q fever patients who had visited the farmers market. To investigate risk factors for infection we conducted a case control study (cases were Q fever patients, controls were randomly selected Soest citizens) and a cohort study among vendors at the market. The sheep exhibited at the market, the herd from which it originated as well as sheep from herds held in the vicinity of Soest were tested for Coxiella burnetii (C. burnetii).A total of 299 reported Q fever cases was linked to this outbreak. The mean incubation period was 21 days, with an interquartile range of 16–24 days. The case control study identified close proximity to and stopping for at least a few seconds at the sheep's pen as significant risk factors. Vendors within approximately 6 meters of the sheep's pen were at increased risk for disease compared to those located farther away. Wind played no significant role. The clinical attack rate of adults and children was estimated as 20% and 3%, respectively, 25% of cases were hospitalized. The ewe that had lambed as well as 25% of its herd tested positive for C. burnetii antibodies.Due to its size and point source nature this outbreak permitted assessment of fundamental, but seldom studied epidemiological parameters. As a consequence of this outbreak, it was recommended that pregnant sheep not be displayed in public during the 3rd trimester and to test animals in petting zoos regularly for C. burnetii.Q fever is a worldwide zoonosis caused by Coxiella burnetii (C. burnetii), a small, gram-negative obligate intracellular bacterium. C. burnetii displays antigenic variation with an infectious phase I and less infectious phase II. The primary reservoir from which human infection occurs consists of sheep, goat and cattle. Although C. burnetii infec
Molecular Modeling of Cell Adhesion Peptides on Hydroxyapatite and TiO2 Surfaces: Implication in Biomedical Implant Devices  [PDF]
Subhashis Biswas, Udo Becker
Journal of Biomaterials and Nanobiotechnology (JBNB) , 2013, DOI: 10.4236/jbnb.2013.44044
Abstract:

Molecular modeling as a tool in studying peptide-substrate interactions provides insight on peptide adsorption conformation, adsorption energy, and stability of the peptide-inorganic interface. This work investigates the hydration and interaction of cell-adhesion peptides, specifically RGD and YIGSR, with the hydroxyapatite surface and TiO2 surface in cluster and periodic boundary condition approaches. The comparison of adsorption energies of RGD and YIGSR on both Hydroxyapatite (HA) and TiO2 surfaces reveals the similarities in adsorption energy and orientation pattern of peptides on both surfaces. The models demonstrate that initial peptide orientation affects adsorption energy for both. YIGSR is consistently more strongly adsorbed to HA-(001) surfaces and steps than RGD for both the surfaces. In addition, RGD maintained its “hairpin”-like structure during adsorption on a flat HA-(001) surface, and a slightly “relaxed hairpin” structure on TiO2 (110) surface. Adsorption energies of RGD on TiO2 (110) surface are significantly more favorable compared to HA-(001) surface, suggesting potential role of TiO2 as biomedical implants when tissue regeneration occurs via cell signaling.

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